Repetitive internet failure

My iphone 5 has been suffering from repetitive internet failure for a long time. I lost hope that a new update gonna fix it. It's now with the newest version of ios, 8.1.3. But the problem actually started much earlier.

About once a week, at a totally random time, all the internet function suddenly stop working. The wifi signal mark still works. It shows full signal when I connected to a wifi and low signal when I move away. A loading circle run forever if you try using any internet related function. I can still disconnect and reconnect to any network but no data can really come through after connected. It happens for my wifi at school, at home and at my friends' house. So it's not dependent on any specific wifi connection. When it happens, it will not switch to LTE automatically. Just loading forever. If I turn off wifi manually, the 3G network won't work either. The wifi mark becomes LTE, but still not a single bit data come through. The only way to solve it is to reset network setting. Once I do that, everything seems back to work, except it fails again within a week.

I'm wondering is it a hardware problem instead of software? It's really getting more an more annoying.